SURFACE EMITTING LASER ELEMENT ARRAY

• US 20100195689A1
• Filed: 09/01/2006
• Published: 08/05/2010
• Est. Priority Date: 03/14/2006
• Status: Active Grant

• Current Assignee: Furukawa Electric Company Limited
• Original Assignee: Furukawa Electric Company Limited
• Inventors: Iwai, Norihiro, Kageyama, Takeo, Ariga, Maiko, Nishikata, Kazuaki
• Granted Patent: US 7,974,327 B2
• Time in Patent Office: Days
• US Class Current: 372/46.01
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01S 2301/176 Specific passivation layers on surfaces other than the emission facet
• CPC Class Codes: H01S 2301/18 Semiconductor lasers with special structural design for influencing the near- or far-field
• CPC Class Codes: H01S 5/02345 Wire-bonding
• CPC Class Codes: H01S 5/0422 with n- and p-contacts on the same side of the active layer
• CPC Class Codes: H01S 5/04257 having positive and negative electrodes on the same side of the substrate
• CPC Class Codes: H01S 5/06226 Modulation at ultra-high frequencies
• CPC Class Codes: H01S 5/18313 by oxidizing at least one of the DBR layers
• CPC Class Codes: H01S 5/18341 Intra-cavity contacts
• CPC Class Codes: H01S 5/423 having a vertical cavity

Abstract

A surface emitting laser element array comprises a plurality of surface emitting laser elements (15) on a same substrate (1) each comprising a mesa post formed of a laminated structure including an active layer (4) for reducing a crosstalk between the surface emitting laser elements constituting the surface emitting laser element array, and for improving a high speed response, wherein each of the surface emitting laser elements (15) comprises a first electrode (9), a second electrode (10) and a third electrode (11) that have a polarity different from that of the first electrode (9); the first electrode (9) is arranged on the mesa post; the second electrode (10) is arranged on one surface of the substrate (1) same as that of the first electrode (9); the third electrode (11) is arranged on the other surface of the substrate (1) opposite to that of the first electrode and the second electrode (9, 10) and is provided as a common electrode of the surface emitting laser elements (15); and an electric current is applied to the active layer (4) using the first electrode (9) and the second electrode (10).

Claims

1. A surface emitting laser element array comprising:

a plurality of surface emitting laser elements on a same substrate each comprising at least a mesa post formed of a laminated structure including an active layer formed of a semiconductor layer,

wherein each of said surface emitting laser elements comprises a first electrode, a second electrode, and a third electrode, said second electrode and said third electrode having a polarity different from that of the first electrode;

said first electrode is arranged on the mesa post;

said second electrode is arranged on one surface of the substrate same as that of the first electrode;

said third electrode is arranged on the other surface of the substrate opposite to that of the first electrode and the second electrode, and is provided as a common electrode of the surface emitting laser elements; and

an electric current is applied to the active layer using the first electrode and the second electrode.

2. The surface emitting laser element array according to claim 1, wherein said second electrode is electrically connected to the third electrode.

3. The surface emitting laser element array according to claim 1, wherein each of said surface emitting laser elements includes a lower part DBR mirror, a lower part cladding layer, the active layer, an upper part cladding layer, and an upper part DBR mirror each sequentially laminated on the substrate;

said lower part DBR mirror is formed of a first lower part semi-insulating DBR mirror of semi-insulating and a second lower part electrically conductive DBR mirror laminated on the first lower part DBR mirror; and

said second electrode is connected to the second lower part DBR mirror.

4. The surface emitting laser element array according to claim 1, wherein each of said surface emitting laser elements is formed of a lower part DBR mirror, a lower part electrically conductive cladding layer, the active layer, an upper part cladding layer, and an upper part DBR mirror each sequentially laminated on the substrate;

and said second electrode is connected to the lower part cladding layer.

5. The surface emitting laser element array according to claim 3, wherein each of said surface emitting laser element further includes a current blocking layer provided in the lower part cladding layer or the upper part cladding layer, or in the lower part DBR mirror or the upper part DBR mirror;

and a current equalizer layer provided at a region near the current blocking layer for equalizing a current distribution in an open part formed of the current blocking layer.

6. The surface emitting laser element array according to claim 5, wherein said current blocking layer and said current equalizer layer are formed in the mesa post.

7. The surface emitting laser element array according to claim 5, wherein said lower part DBR mirror or said upper part DBR mirror is formed of a p-type semiconductor, and said current equalizer layer is provided in the lower part DBR mirror or the upper part DBR mirror formed of the p-type semiconductor and on a side of the current blocking layer opposite to the active layer.

8. The surface emitting laser element array according to claim 7, wherein said p-type semiconductor includes a semiconductor formed in a layered structure as represented with p-Al_xGa_1-xAs/p-Al_yGa_1-yAs (0≦

x≦

1, 0≦

y≦

1).

9. The surface emitting laser element array according to claim 5, wherein said current equalizer layer has an electrical resistivity lower than that of a layer constituting at least one of the lower part DBR mirror and the upper part DBR mirror.

10. The surface emitting laser element array according to claim 5, wherein said current equalizer layer has an electrical resistivity higher than that of a layer constituting at least one of the lower part DBR mirror and the upper part DBR mirror.

11. The surface emitting laser element array according to claim 5, wherein said current equalizer layer is formed of a layered structure including a low electrical resistivity layer having an electrical resistivity lower than that of a layer constituting at least one of the lower part DBR mirror and the upper part DBR mirror, and a high electrical resistivity layer having an electrical resistivity higher than that of the layer and is arranged as a layer between the current blocking layer and the low electrical resistivity layer.

12. The surface emitting laser element array according to claim 5, wherein said current equalizer layer is formed of one layer constituting the lower part DBR mirror or the upper part DBR mirror, or an interface of the one layer with an impurity of not less than 5×

10¹⁸ cm<sup>−

3</sup> doped therein.

13. The surface emitting laser element array according to claim 12, wherein said impurity includes at least one of C, Zn and Be.